<template>
    <fieldset>
        <legend>vue3选项式methods</legend>
        <button>-</button>
        <b>{{num}}</b>
        <button @click="increase">+</button>
    </fieldset>
</template>

<script setup>
import {ref} from "vue"
let num = ref(10)
let increase = function (){
    num.value++
}
</script>